The purpose of this study is to examine further the mechanism wherein injection of hydralazine and one of its major metabolites conjugated to human serum albumin induces and immune reaction to various nuclear antigens. It is hoped to gain insight into the development of spontaneous systemic lupus erythematosus as well as to increase our understanding of the general concepts of autoimmunity. An attempt will be made to induce clinical SLE in rabbits with an hydralazineHSA compound. These rabbits will be studied for antibodies against DNA and nuclear constituents and antibodies directed against other self antigens. These rabbits will have both the specific and nonspecific cellular immune reactions studied sequentially. A second objective will be to establish if tolerance is broken to DNA in rabbits immunized with hydralazine-HSA. The rabbits will be injected with other metabolites of hydralazine coupled to HSA to see if DNA antibodies are produced. Finally, the A/Jax mouse will be used in an attempt to induce immune reactions to DNA by injections of hydralazine-HSA to see if the phenomena can be induced in other species. BIBLIOGRAPHIC REFERENCES: Foad, B.S.I., Litwin, A., Zimmer; H. and Hess, E.V.: Acetylator Phenotype in Systemic Lupus Erythematosus. Arth. & Rheum., March/April 1977. Litwin, A.: Hydralazine Induced Systemic Lupus Erythematosus. Human Disease and Experimental Considerations. In "Immunopharmacology," Spectrum publishers, Philadelphia, Pa. 1976.